Magnetic memory device
View Patent ↗The present invention provides a magnetic memory device capable of providing high-speed access without increasing an array area. Gate word lines are respectively linearly disposed between source impurity regions and drain impurity regions within a memory cell array area. Gate word line protrusions are respectively provided at boundary regions of memory cell forming regions. Contacts relative to the gate word line protrusions are respectively provided at boundary regions of memory cells at adjacent columns. The drain impurity regions are respectively disposed with being shifted from the centers of the memory cell forming regions in such a manner that spaces between the drain impurity regions become large in the regions in which the protrusions are disposed.
1. A magnetic memory device comprising:
a plurality of MRAM cells arranged in matrix form and each having a series body of a variable magnetoresistive element and a selection transistor;
a plurality of word lines disposed corresponding to respective rows of the MRAM cells and coupled with gates of the selection transistors of the MRAM cells of the corresponding rows respectively; and
a plurality of piling wirings provided corresponding to the word lines and electrically coupled to the corresponding word lines at predetermined intervals,
wherein at each of the MRAM cells, the selection transistor has first and second impurity regions disposed opposite to each other,
wherein the corresponding word lines are disposed so as to cross between the first and second impurity regions along a row direction to thereby configure the gates,
wherein the first impurity regions are disposed in separated form every MRAM cells along the row direction and electrically coupled to their corresponding variable magnetoresistive elements,
wherein each of the MRAM cells has first and second adjacent MRAM cells adjacent in the directions opposite to each other in the row direction, and
wherein a first distance L 1 in the row direction to each of the first impurity regions of the MRAM cell and the first adjacent MRAM cell is longer than a second distance L 2 extending along the row direction to each of the first impurity regions of the MRAM cell and the second adjacent MRAM cell.
2. The magnetic memory device according to claim 1 ,
wherein at the respective MRAM cell rows, the second impurity regions continuously extend in the row direction and thereby form common source regions with respect to the selection transistors of the MRAM cells of the corresponding rows respectively, and
wherein the magnetic memory device further comprises source piling wirings which are disposed in regions between the first impurity regions each having the second distance L 2 in association with columns of the MRAM cells so as to extend continuously in a column direction and which are respectively electrically coupled to the second impurity regions in regions which intersect with the second impurity regions.
3. The magnetic memory device according to claim 2 ,
wherein a relationship of distances extending along the row direction between contacts for providing electrical coupling between the first impurity regions and the corresponding variable magnetoresistive elements is set to a relationship opposite to a relationship of the first and second distances L 1 and L 2 extending along the row direction between the first impurity regions among transfer MRAM cells.
4. The magnetic memory device according to claim 1 ,
wherein each of the word lines has a protrusion which extends to a boundary region of each MRAM cell column in a region between the first impurity regions each having the first distance L 1 , and
wherein contacts for providing electrical coupling between the word line piling wirings and their corresponding word lines are formed at MRAM cell column boundary portions of the protrusions.
5. The magnetic memory device according to claim 4 ,
wherein the protrusions are formed so as to extend in an opposite direction every the MRAM cells and formed at positions different in the row direction at the adjacent rows.
6. The magnetic memory device according to claim 1 , further comprising source piling wirings disposed in regions between the first impurity regions each having the second distance L 2 in association with the MRAM cell columns so as to extend continuously in the column direction,
wherein at the respective MRAM cell rows, the second impurity regions continuously extend in the row direction and thereby form common source regions with respect to the selection transistors of the MRAM cells of the corresponding rows respectively,
wherein the source piling wirings are respectively electrically coupled to the second impurity regions in regions which intersect with the second impurity regions,
wherein each of the word lines has a protrusion of the same wiring layer as the source piling wiring, extending to a boundary region of each MRAM cell column in a region between the first impurity regions each having the first distance L 1 , and
wherein contacts for providing electrical coupling between the word line piling wirings and their corresponding word lines are formed at MRAM cell column boundary portions of the protrusions respectively.
7. The magnetic memory device according to claim 1 ,
wherein wirings for coupling the first impurity regions and their corresponding variable magnetoresistive elements respectively have the same pattern at the memory cells of each adjacent row.